Pyrimidine substituted urea complexes and processes for preparing the same



try, 2nd edition, 1950, p. 595).

United States Patent PYRIMIDINE SUBSTITUTED UREA COMPLEXES AND PROCESSES FOR PREPARING THE SAME Arthur J. Basso, Colonia, N. 3., and Robert C. ONeill,

New York, N. Y., assignors to Merck & Co., Inc, Rahway, N. 1., a corporation of New Jersey No Drawing. Application December 29, 1954, Serial No. 478,514

20 Claims. (Cl. 167-531) This'invention relates to novel pyrimidine-substituted urea complexes and to the processes for preparing these novel compounds.

This application is a continuation-in-part of patent application Serial No. 399,152, filed December 13, 1953, now abandoned.

'It has been found that. these pyrimidine-substituted urea complexes possess marked and effective action in the control and treatment of the disease coccidiosis which infects poultry.

The novel pyrimidine-substituted urea complexes with which this invention is concerned may be represented by the following structural formula: r

O NH NH R R wherein R ishydrogen or a lower alkyl group, R is an electron withdrawing group and Xis oxygen or sulfur.

These pyrimidine-substituted urea complexes are new chemical compounds. They are equimolar complexes which have their own characteristic properties that are markedly different from the component parts and are not mere mixtures of a pyrimidine and a substituted urea.

These novel pyrimidine-substituted urea complexes are produced byreacting a substitutedurea compound represented by the formula-- wherein R is hydrogen or a lower alkyl group and R is an electron withdrawing group, with a pyrimidine compound represented by the formulagroup's.- Such groups are alternatively referred to as meta directing (see Fieser and Fieser, Organic Chemis- Specific carbanilicle compounds which may be employed include 4,4'-dinitroice 2 carbanilide; 2-methyl-4,4-dinitrocarbanilide; 4-nitro-4- cyanocarbanilide; and 4-nitro-4'-acetocarbanilide.

Examples of pyrimidine compounds which may be employed in this invention include 2-hydroxy-4,6-dimethylpyrimidine; Z-hydroxypyrimidine; 2mercapto-4,6-dimethylpyrimidine; 2-hydroxy-4-methylpyrimidine; and 2-hyroxy-4,6-diethylpyrimidine.

in accordance with one procedure for carrying out the process of this invention, the solid substituted urea compound is reacted with a solution of the: pyrimidine compound; The reaction mixture in which the substituted urea compound is ordinarily insoluble or very slightly soluble is stirred until the insoluble complex is formed. The insoluble pyrimidine-substituted urea complex is then filtered, washed and dried.

The reaction solvent is not critical. Ethers such as dioxane and ethyl ether, alcohols such as the lower aliphatic alcohols, hydrocarbons such as benzene, toluene, Water and mixtures of such solvents may be employed satisfactorily. It'has been. found advantageous to employ a solvent in which the pyrimidine is' soluble and in which the substituted urea is insoluble.

As the substituted urea compound it is preferred to employ 4,4'-dinitrocarbanilide, although other carbanilides having different electron withdrawing groups in the 4 and 4-positions may be used. Typical substituents which may be present in these positions are nitro, cyano, carboxyl, and carboalkoxyl radicals. Furthermore, the electron withdrawing groups at the 4 and 4-positions need not be the same. Thus, typical examples of 4,4- disubstituted carbanilides useful in this invention are 4,4 dinitrocarbanilide; 4,4-dicyanocarbanilide; and 4-nitro- 4-cyanocarbanilide.

The pyrimidine-substituted urea complexes prepared in accordance with this invention are active against the widespread poultry disease commonly called coccidiosis which is caused by species of protozoan parasites of the genus Eimeria. In this regard, E. tenella is responsible for a severe and frequently fatal infection of the caecum of chickens. Furthermore, other serious infections are caused in fowl by other species of Eimeria and especially E. acervulina, E. necatrix, E. maxima, and E. brunetti. if left untreated, such infections often cause extensive losses of fowl. The elimination or control of coccidiosis is, therefore, of the utmost importance for successful poultry raising.

According to a further embodiment of this invention, novel compositions useful in the treatment of coccidiosis are provided containing a pyrimidine-substituted urea complex as an active ingredient. These compositions comprise a pyrimidine-substituted urea complex intimately combined with an inert carrier. In this regard compositions which contain a compound of the formula O NniiNH R n n R p R/G QR in:

wherein R is hydrogen or a lower alkyl group, R is an electron withdrawing group, and X is oxygen or sulfur,

, as the active ingredients have been found to be particularly useful against coccidiosis.

These compositions comprise at least one of the pyrimidine-substituted urea complexes mentioned above combined with an inert carrier or diluent. Such compositions are conveniently produced by intimately dispersing the active ingredient throughout a carrier. The carrier or diluent may be either liquid or solid. Liquid dispersions can be prepared satisfactorily by using emulsifiers and surface active agents. Any solid can be used as a carrier which is inert toward the active compounds and which can be administered to animals with safety. Examples of suitable carriers are ground oyster shells, Attapulgus clay, and edible vegetable materials such as commercial animal and poultry feeds, urea, corn meal, ground corn, citrus meal, fermentation residues and dis tillers dried grains. The active ingredient is conveniently dispersed in a solid carrier by conventional methods such as stirring, tumbling, and grinding. In this manner, by selecting different carriers and by altering the ratio of carrier to active ingredient, compositions of varying concentration can be prepared. Compositions very suitable for addition to poultry feed may contain from about 5% to about 40% of the new coccidiostat, and preferably about 25%, adsorbed on or mixed with a carrier. Premixes of 4,4-dinitrocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex may be prepared as referred to above in a general manner. Two satisfactory formulations are described in detail below.

hydroxy 4,6 dia. 300 pounds 4,4'-dinitrocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex b. 175 pounds corn distillers dried grains (through 30 mesh screen) Q a. 455 pounds wheat shorts (30-80 mesh) (1. 70 pounds dried vitamin B12 fermentation solubles (30-80 mesh) B. Ingredients:

a. 4,4 dinitrocarbanilide-Z hydroxy 4,6 dimethylpyrimidine complex b. Corn distillers dried grains Preparati0n.--The following quantities are employed in order to make 995 pounds of product:

a. 250 pounds 4,4-dinitrocarbanilide'2-hydroxy-4,6-dimethylpyrimidine complex b. 188 pounds corn distillers dried grains (through 30 mesh screen) c. 487 pounds wheat shorts (30-80 mesh) (1. 70 pounds dried vitamin B12 fermentation solubles (30-80 mesh) i The actual operating conditions are as in A.

Products such as the above are suitable for incorporation into poultry feedstuffs in order to obtain the desired dosage level of active drug.

The amount of active ingredient required for effective prophylactic control of coccidiosis is very low. With regard to poultry, good results have been obtained by the administration of a quantity of the active ingredient equal to about 0.005% to 0.05% of the food consumed. Optimum results are usually obtained by the daily administration of a quantity of active ingredient equal to about .0075 to about .025% of the food consumed. Such relatively small amounts may be conveniently incorporated in the normal ration prior to feeding thepoultry. Larger concentrations of up to about 0.1% of the active ingredient may be employed if an outbreak of the disease is encountered.

The coccidiostatic activity of compositions containing various pyrimidine-substituted urea complexes was experimentally demonstrated according to the following test:

Groups of 10 two-week old chicks were fed a mash feed containing from 0.01% to 0.04% of the active ingredient uniformally dispersed therein; After existing on the diet fOI24 hours, each chick was inoculated with 50,000 sporulated oocyst of E. tenella. In addition, groups of'l0 chicks were also infected but fed a diet free of the active ingredient and used as positive controls. Still other groups were treated separately with the substituted urea compound, and the pyrimidine compound and with physical mixtures of the substituted urea compound and the pyrimidine compound. The experiment was terminated after administering the respective diets for seven days after inoculation and the following results were obtained: The oocyst count (number of parasites of E. tenella remaining) was determined by sacrificing the birds and examining the infected organs microscopically.

TABLE 1.--ANTICOCCIDIAL TESTING RESULTS P 8 cent Percent Mortality Oocyst Count X 10' Percent Weight Gain om- Compound pound Um Un Un- In Diet Treated treated Treated mated Treated treated 0. 1 0 40 20 34. 17 6O 45 44'-dinitrocarbanillde 0. 05 0 40 28 34 66 45 0.025 20 40 29* 34. 54 45 A physical mixture of 4,4-dinltrocarbanilide 0. 07

an 2-hydroxy-4,G-dimethylpyrlml- 0 27 H 16 a dim 8' 0 20 o 1 1 a l6. 5 4,4'-d1n1trocarb anillde- 2-11 ydroxy- 4,6-dimethylpyrimidine complex g'gf g 38 8 $3 3 (Gmpmmd Example 1) 0101 0 a0 2 0 l6: 1 es as 4,4"dinitrocarbanilide- Z-hydroxypyrimidine complex (Compound of Example 2) 0 04 0 40 0.2 11 7 40 34 4,fggltrottiurpanilideamercaptiome y pyrimi inc comp ex 7 I wompmdmmwea 4 8:8; 3 a a it; a a

c. Wheat shorts d. Dried vitamin B12 fermentation solubles C0mp0sz'ti0n.-Each pound of the mixture contains 0.25 pound of coccidiostat.

plex. 5 It has also been shown that mere physical mixtures'of It will be noted from Table I that 4,4-dinitrocarbanilide when administered separately does have activity but such activity does not approach that displayed by the com- The complexing agents of themselves are inactive.

5 4,4 -dinitrocarbanilide and a complexing agent do not have anticoccidial activity any greater than is obtained with 4,4'-dinitrocarbanilide alone.

A second experiment to determine the effectiveness against coccidiosis of 4,4'-dinitrocarbanilide-2-hydr0xy- 4,6-dimethylpyrimidine complex under field conditions was carried out, as follows:

A group of 1000 chickens was used as the controlwhile a second group of 600 chickens was; treated by incorporation into the feed of 0.009% 4,4'-dinitrocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex. All of the birds were challenged by artificial exposure to. coccidiosis at two weeks of age. The results when the birds had reached ten Weeks of age appear in Table II.

A third experiment consisted of twenty pens of 800 chickens each divided asfollows:

a. 4 pens received no medication and served as controls.

b. 4 pens received 0.015% 4,4'-dinitrocarbani lide-Z-hydroxy-4,6-dimethylpyrimidine complex continuously in thefeed.

c. As b plus 25- gm. of penicillin per ton of feed intermittently.

a. As 5 plus 100 gm. of streptomycin per ,ton of. feed intermittently.

e. As b plus 25 gm. of penicillinand 75 gm. of streptomycin per ton of feed intermittently.

The birds were artificially infected with coccidiosis at two weeks of age. The mortalityand morbidity due to coccidiosis in each pen at ten weeks of ageis shown below (Table III).

TABLE III Pen Mortality Morbidity Group N 0. (percent) (percent) 1 3. 25 25 I i 2 6. 25 50 a 3 v c. s3 4 1 0. 0 0

Average.

In still a fourth experiment at' a commercial poultry farm 3250 chickens were divided into three separate pens, two of which were treated with 4,4'dinitrocarbanilide-2- hydroxyt,6-dimethylpyrimidine complex in the, feed. Naturally occurring coccidiosiswas dependedupon. for the challenger The divisionof the birds into-pens and inci dence of morbidity due to 'coccidiosis is shown in Table IV below.

The following examples are intended to be illustrative only and may be varied or modified without departing from the spirit and scope of this invention:

Example I 4.4 DINITRO CARBANILIDE-2-HYDtROXY-4,6-DIMETHYL- PYRIMIDINE COMPLEX 144 grams (0.90 mol) of 2-hydroxy-4,6-dimethylpyrimidine dihydrate were dissolved in a mixture of 1000 ml. of toluene and 560 ml. of ethanol at room temperature. The solution was stirred and 181.2 grams (0.60 mol) of 4,4'-dinitrocarbanilide was: added.

The resulting slurry was stirred at room temperature for a total of ten and one-half hours, and then filtered with vacuum. The egg yoke-yellow 4,4--dinitrocarbanilide'2-hydroxy-4,6-dimethylpyrimidine complex thus obtained was washed with ether, and air-dried to constant weight to yield 232 grams (91%) of said product. The 4,4 dinitrocarbanilide 2 hydroxy 4,6 dimethylpyrimidine complex melted with decomposition at about 265 C- in a sealed capillary.

Purity and identity of 4,4'-dinitrocarbanilide-2-hydroxy- 4,6-dimethylpyrimidine was established by ultraviolet assay of the components employing sulfuric acid as the solvent. Calculated 29.1%; found 29.2%.. Analysis cal- Culated for C19H18N606Z C, 53.5; H, 4.26; N, 19.7. Found: C, 53.63; H, 4.30; N, 19.75.

A premix was prepared by blending 10% of 4,4'- dinitrocarbanil'ide 2 hydroxy 4,6 dimethylpyrimidine complex, 10% molasses solubles and com distillers dry grain. The molasses solubles is not critical and mixtures of 10-20% of 4 ,4-dinitrocarbanilide-2-hydroxy- 4,6-dimethylpyrirnidine complex and 8090% corn distillers dry grain would be satisfactory. Wheat shorts, whole ground corn or corn cob meal may be substituted for the corn distillers dry grain. The amount of active ingredient may. bevaried to approximately 25% of the complete mixture.

'7 Example 2 4,4 -DINI'IROCARBANILIDE- Z-HYDROXYPYRIMIDINE COMPLEX O ONE; NH

N O IN/ \N a V NniiNn m l N om I /\NO2 (in To a solution of 3.84 grams (0.04 mole) of Z-hydroxypyrimidine in 75 ml. of ethanol was added with stirring 9.06 g. (0.03 mole) of 4,4'-dinitrocarbanilide. The bright yellow slurry was stirred at room temperature for approximately 16 hours and filtered. The cake, consisting o1" finely divided 4,4'-diniifOCaIbanilid6Z-hYdIOXY-PYIiIDidine equirnolar complex, was washed with ethyl acetate, then dried to constant Weight to yield 10.6 g. (89%) of the desired product. Analysis calculated for CnI-ImOsNe: C, 51.2; H, 3.55; N, 21.1. Found: C, 50.9; H, 3.47; N, 21.28.

A premix may be prepared by blending 10% of the 4,4-dinitrocarbanilide-Z-hydroxy-pyrimidine complex and 90% corn distillers dry grain.

Example 3 4,4-DINI'ILROCARBANILIDEZ-MERCAPTO-4,G DIMETHYL- V PYRIMIDINE COMPLEX o NHi lNH Know/CH5 O l g) I N N 0m N01 0 V NHENH HECWCH: V bi N f o NOi A/ I for eight hours.

Example 4 2-METHYL-4,4'-DINITROCARBANILIDE-2-HYDROXY-4fi- DIMETHYLPYRIMIDINE COMPLEX 10 grams of 2-hydroxy-4,6-dimethylpyrimidine was dissolved in a minimum of ethanol. The mixture was stirred and 12.64 grams of 2-methyl-4,4'-dinitrocarbanilide was added. The slurry thus obtained was stirred for approximately 16 hours and filtered. The cake consisting of 2 methyl 4,4 dinitrocarbanilide-Z hydroxy 4,6- dimethylpyrimidine complex was washed with ethyl acetate and then dried to constant weight to yield a product having a melting point of 2 l0-215 C. (with decomposition).

The starting material 2-methyl-4,4-dinitrocarbanilide was prepared, as follows: V 30.0 grams (0.197 mol) of 2-rnethyl-4-nitroaniline and 31.9 grams (0.194 mol) of para-nitrophenylisocyanate was stirred with 500 ml. of toluene at reflux temperature formed gradually during this reaction was collected by vacuum filtration, washed with dry toluene, and dried to constant weight to yield 2-methyl-4,4 -dinitrocarbanilide having a melting point of 275-277 C. (with decomposition).

dinitrocarbanilide-Z mercapto 4,6 -;dimethylpyrimij dine complex and 90% wheat shorts.

was prepared by acetone recrystallization.

Analysis calculated for C14H1205N4Z C, 53.18; H, 3.82; N, 17.72. Found: C, 53.14; H, 3.52; N, 17.52.

A premix may be prepared by blending 10% of 2- methyl 4,4 dinitrocarbanilide'2 hydroxy 4,6 dimethylpyrimidine complex and corn cob meal.

Example 5 4-NITRO-4'-CYANOCARBANILIDE-2-HYDROXY-4,6-DI

METHYLPYRIMIDINE COMPLEX l N om ON 0 nm lm ERGWGH; O O N oin ON on 12 grams of 2-hydroxy-4,6-dimethylpyrimidine was dissolved in a minimum of ethanol and 14.1 grams of 4- nitro-4-cyanocarbanilide was added. The reaction mixture was stirred at room temperature for approximately 16 hours and filtered. The cake consisting of finely divided 4 nitro 4' cyanocarbanilide'2 hydroxy 4,6- dimethylpyrimidine complex, was washed with ethyl acetate', and then dried to constant weight to yield a product having a melting point of'244.5 C. (with decomposition).

The yellow crystalline product which- An analytical sample of 2-methyl-4,4'-dinitrocarbanilide" The starting material 4.-nitro--4'-cyanocarbanilide was prepared as follows: 1 r i 24.6 grams 1. (0.15, mol) of 5 para-nitrophenylisocyanate was dissolved in 375 ml. of dry toluene and.17.7. grams (0.15 mol) of ,para-aminobenzonitrile, was added. The mixture was stirredat reflux ,forthree hours,,cooled to room temperature and. filtered. Thefilter cake of light yellow 4-nitro-4f-cyanocarbanilide was washed M well with dry toluene and dried. to constant weight to yield a producthaving a melting; point of 2.95-2 98NC. (with decomposition). p r 1 An analytical sample pf 4-nitro-4Qcyanocarbanilide was prepared by recrystallization frorrracetone. This producthad aqmelting, point of 298600 .C. (with de: composition). U r

Analysis calculated for CirHioOaN z ,C, 59.61; .H, 3.57; N, 19.86. Found: C, 59.49; H,,3.52; N,,19 .69. A premix may .bepreparedby blending, 4- nitro-4f-cyan ocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex and any of the carriersmentioned in Example 1. 1

4-NI'rRoA ACETOCARBANILIDE'z-nrnnoxr-ge m- METHYLPYRIMIDINE COMPLEX ants I r NO,

12.0 grams of 2-hydroxy-4,6-dimethylpyrimidine was dissolved in a of ethanol and 14.9 grams of 4-nitro-4-acetocarbanilide was added. The reaction mixture was stirred at room temperature for approximately 16 hours and filtered. The cake consisting of 4-nitro-4- acetocarbanilide-2-hydroxy-4,G-dimethylpyrimidine complex was washed wth ethyl acetate, and then dried to constant weight to yield a product having a meltingpoint f2l3-216C. W it i The starting material4-nitro-4acetocarbanilide .was

prepared, asfollows:

27 grams (0.2 mol): of dryzpara-aminoacetophenone was added to a clearsolution of 31.3ugrams (0.191 mol) of para-aminophenylisocyanate in 500 ml. of :dry toluene, after one hour refluxing and stirring the mealy solid mass of crystalline 4-nitro-4' -acetocarbanilide was collected by vacuum filtration, washedlwith tolueneand dried to constant weight The .4-nitro-4'-acetonitrocarbanilide thus obtained had a melting point of 247-260" C. (with decomposition).

A premix may be prepared by blending 4-nitro-4'- acetocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex and any of the carriers mentioned in Example 1.

Various changes and modifications may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the purview of the annexed claims, they are to be considered as part of this invenn'on.

What is claimed is:

1. Acompound of the formula-- 10 wherein R is selected from the group consisting of hydrogen and lower alkyl groups, R is an electron withdrawing group, and X is selected from the group consisting of oxygen and sulfur.

2. A compound of the formulawherein R is selected from the group consisting of hydrogen and lower alkyl groups and R is: an electron withdrawing group, at least oneR' being a nitro group, and X is selected from the group consisting of oxygen and sulfur.

.3. .A compound of the formula- 0 NH NH R R R W N om N01 n wherein R is selected from the group consisting of hydrogen and lower alkyl groups and X is selected from the group consisting of oxygen and sulfur.

4. 4,4 dinitrocarbanilide-Z hydroxy 4,6 dimethylpyrimidine complex.

5. 4,4 dinitrocarbanilide-2 hydroxypyrimidine complex.

6. 4,4 dinitrocarbanilide'2 mercapto 4,6 dimethylpyrimidine complex. 7. 2 methyl 4,4 dinitrdcarbahilide-Z hydroxy 4;6 dimethylpyrimidine complex. i

8. 4 nitro 4' cyanocarbanilide-2 hydroxy 4,6 dimethylpyrimidine complex.

9. The process which comprises reacting a compound represented by the formulawherein R is selected from the group consisting of hydrogen and lower alkyl groups and R is an electron withdrawing group with a compound represented by the formula-- RWR wherein R is as above and X is selected from the group consisting of oxygen and sulfur to form a complex represented by the formula- NHENH R n a u R R \(I wherein R, R and X are as above.

, '11 10. The process which comprises reacting a compound represented by theformula wherein R is as above and X is selected from thegroup consisting of oxygen and sulfur to'form a complex represented by the formula w NHENH R (YR R I wherein R, R, and X are as above.

11. The process which comprises reacting a compound represented by the formula- 0 i i V ma ma 1 s u f 0,5: i No,

wherein R is selected from the group consisting of hydrogen and lower alkyl groups with a compound represented by the formulaawn V.

' wherein R is as above and X is selected from the group consisting of oxygen and sulfur to form a complex represented by the formula 0 ma ma R it R R s N om NO| 11 wherein R and X are as above.

12. The process which comprises reacting -4,4-dinitro' carbanilide with 2-hydroxy-4,o-dimethylpyrimidine to form 4,4-dinitrocarbanilide-2-hydroxy-4,6-dimethylpyrimidine complex. v 1 r 13. The process which comprises reacting 4,4'-'dinitrocarbanilide with Z-hydroxy-pyrirnidine to form 4,4 -dinitrocarbanilide-2-hydroxypyrimidine complex.

14. The process which comprises reacting 4,4'-dinitrocarbanilide with Z-mercapto-4,6-dimethylpyrimidine to form 4,4'-dinitrocarbanilide-2-mercapto-4,G-dimethyl-pyrimidine complex. I

15. The process which comprises reacting 2-methyl- 4,4'-dinitrocarbanilide with 2-hyd'roxy-4,6-dimethylpyrimidine to form 2-methyl-4,4'-dinitrocarbanilide-2-hydroxy- 4,6-dimethylpyrimidine complex. 7

16. The process which comprises reacting 4-nitro-4'- cyanocarbanilide with 2-hydroxy-4,6-dimethylpyrimidine to form 4-nitro-4Fc'yanocarbanilide-2-hydroxy-4;6-dimethyl pyrimidine complex'. 1 y

17. A composition useful against coccidiosis which comprises an inert carrier anda compound represented by the formula GNH NH RWR N in; I B! V wherein R is selected from the group consisting of hydrogen and lower alkyl groups, R' is an electron withdrawing group andX is selected from the group consisting of oxygen and sulfur.

18. A composition useful against coccidiosis which comprises an animal feedstuff and a compound represented by the formula A I NHENk R R e u No references cited. 

17. A COMPOSITION USEFUL AGAINST COCCIDIOSIS WHICH COMPRISES AN INERT CARRIER AND A COMPOUND REPRESENTED BY THE FORMULA 